Receiving Serial

heathclf

Hello all,

I've posted before, but am still very new to microcontrollers. I'm trying to receive string / numbers / whatever from my pc to my propeller chip. I'm using FullDuplexSerial, just because, but can't get it to work.

My code is really just:

Debug.rx
Debug.str(string(rxbyte))

Where:

OBJ

Debug: "FullDuplexSerial"

and

PUB rx : rxbyte

'' Receive byte (may wait for byte)
'' returns $00..$FF

repeat while (rxbyte := rxcheck) < 0

I keep getting errors. Any help would be much appreciated. When replying, please don't assume I know too much.

Thanks.

tpw_man

You cannot declare a string's contents when the Propeller is running. When the code is compiled and downloaded to the Propeller chip, the compiler puts the text into memory. You can do this: 'debug.tx(debug.rx)' That will echo any character that the Propeller receives.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
I am 1011, so be surprised!


Advertisement sponsored by dfletch:
Come and join us on the Propeller IRC channel for fast and easy help!
Channel: #propeller
Server: irc.freenode.net or freenode.net
If you don't want to bother installing an IRC client, use Mibbit. www.mibbit.com

heathclf

Checked more documentation, and figured it out. Problem solved, but I do have another that is pretty annoying. In order to communicate with my computer, the serial lines from my Propeller chip uses reversed logic, whereas my RS232 uses normal logic. I have to take the logic through an inverter, which seems silly to me. There are modes, in the library FullDuplexSerialPlus, which can be supposedly changed, but it doesn't seem to. I put a scope on my output, and get the identical signal, which won't communicate with my computer. As soon as I take it through an Inverter, it works just fine.

Here's some source code from the library:

PUB start(rxpin, txpin, mode, baudrate) : okay

'' Start serial driver - starts a cog
'' returns false if no cog available
''
'' mode bit 0 = invert rx
'' mode bit 1 = invert tx
'' mode bit 2 = open-drain/source tx
'' mode bit 3 = ignore tx echo on rx

stop
longfill(@rx_head, 0, 4)
longmove(@rx_pin, @rxpin, 3)
bit_ticks := clkfreq / baudrate
buffer_ptr := @rx_buffer
okay := cog := cognew(@entry, @rx_head) + 1

using a 1 or a 0 doesn't seem to invert the output. How can I accomplish this?

Thanks a lot.

Erik Friesen

A 1 is 1 in binary. How about trying a %11, or 3? which would invert rx and tx